#include "line-editor.h"

#include "keybind.h"

/*** PRIVATE FUNCTIONS ********************************************************/

static void line_ed_set_cursor(
	struct bshell_line_ed_p *ed,
	unsigned long cursor);
static fx_value line_ed_get_data(
	const struct bshell_line_ed_p *ed,
	const char *key);
static enum bshell_status line_ed_put_data(
	struct bshell_line_ed_p *ed,
	const char *key,
	fx_value value);

static void clear_cache(struct bshell_line_ed_p *ed)
{
	fx_string_unref(ed->ed_cache.c_prompt);
	fx_string_unref(ed->ed_cache.c_buffer);
	memset(&ed->ed_cache, 0x0, sizeof ed->ed_cache);
}

static enum bshell_status line_ed_readline(
	struct bshell_line_ed_p *ed,
	fx_string *out)
{
	ed->ed_flags &= ~(LINE_ED_DONE | LINE_ED_EOF);
	fx_tty_set_mode(ed->ed_tty, FX_TTY_RAW);

	clear_cache(ed);
	fx_string *prompt = line_ed_get_prompt(ed);
	fx_string *buffer = line_ed_get_buffer(ed);

	fx_string_clear(buffer);
	line_ed_set_cursor(ed, 0);

#define SHOULD_CONTINUE(ed) (!(ed->ed_flags & (LINE_ED_DONE | LINE_ED_EOF)))
	while (SHOULD_CONTINUE(ed)) {
		line_ed_hide(ed);
		line_ed_show(ed);
		fx_tty_flush(ed->ed_tty);
		fx_keycode key = fx_tty_read_key(ed->ed_tty);

		line_ed_handle_key(ed, key);
	}
#undef SHOULD_CONTINUE

	long shift_y = (long)ed->ed_render.ed_points.c_cursor_limit_y
	             - (long)ed->ed_render.ed_points.c_cursor_y + 1;
#if 0
	fprintf(stderr,
	        "cursor_y=%lu, cursor_limit_y=%lu, shift_y=%ld\n",
	        ed->ed_render.ed_points.c_cursor_limit_y,
	        ed->ed_render.ed_points.c_cursor_y,
	        shift_y);
#endif

	fx_tty_putc(ed->ed_tty, 0, '\r');
	for (long i = 0; i < shift_y; i++) {
		fx_tty_putc(ed->ed_tty, 0, '\n');
	}

	fx_tty_flush(ed->ed_tty);

	fx_tty_set_mode(ed->ed_tty, FX_TTY_CANONICAL);
	buffer = line_ed_get_buffer(ed);

	if (out) {
		fx_string_append_s(out, buffer);
	}

	return BSHELL_SUCCESS;
}

static struct bshell_line_source *line_ed_get_line_source(
	struct bshell_line_ed_p *ed)
{
	return &ed->ed_linesrc;
}

unsigned long line_ed_get_cursor(const struct bshell_line_ed_p *ed)
{
	enum bshell_status status = BSHELL_SUCCESS;
	fx_value v = line_ed_get_data(ed, "cursor");
	if (!fx_value_is_set(&v)) {
		status = line_ed_put_data(
			(struct bshell_line_ed_p *)ed,
			"cursor",
			FX_ULONG(0));
		return 0;
	}

	unsigned long cursor = 0;
	fx_value_get_ulong(&v, &cursor);
	fx_value_unset(&v);

	return cursor;
}

static void line_ed_set_cursor(
	struct bshell_line_ed_p *ed,
	unsigned long cursor)
{
	line_ed_put_data(ed, "cursor", FX_ULONG(cursor));
}

static unsigned long line_ed_move_cursor(
	struct bshell_line_ed_p *ed,
	long move_amount)
{
	unsigned long cursor = line_ed_get_cursor(ed);
	fx_string *buffer = line_ed_get_buffer(ed);

	if (move_amount < 0) {
		if (labs(move_amount) > cursor) {
			cursor = 0;
		} else {
			cursor += move_amount;
		}
	} else {
		unsigned long max
			= fx_string_get_size(buffer, FX_STRLEN_CODEPOINTS);
		if (cursor + move_amount > max) {
			cursor = max;
		} else {
			cursor += move_amount;
		}
	}

	line_ed_put_data(ed, "cursor", FX_ULONG(cursor));
	return cursor;
}

static enum bshell_status line_ed_set_done(struct bshell_line_ed_p *ed)
{
	ed->ed_flags |= LINE_ED_DONE;
	return BSHELL_SUCCESS;
}

static enum bshell_status line_ed_set_eof(struct bshell_line_ed_p *ed)
{
	ed->ed_flags |= LINE_ED_EOF;
	return BSHELL_SUCCESS;
}

static bool line_ed_is_done(const struct bshell_line_ed_p *ed)
{
	return (ed->ed_flags & LINE_ED_DONE) == LINE_ED_DONE;
}

static bool line_ed_is_eof(const struct bshell_line_ed_p *ed)
{
	return (ed->ed_flags & LINE_ED_EOF) == LINE_ED_EOF;
}

static fx_value line_ed_get_data(
	const struct bshell_line_ed_p *ed,
	const char *key)
{
	if (!ed->ed_data) {
		return FX_VALUE_EMPTY;
	}

	bshell_line_ed_plugin_class *ops = fx_object_get_interface(
		ed->ed_data,
		BSHELL_TYPE_LINE_EDITOR_PLUGIN);
	if (!ops || !ops->p_get_data) {
		return FX_VALUE_EMPTY;
	}

	fx_value result = FX_VALUE_EMPTY;
	enum bshell_status status
		= ops->p_get_data(ed->ed_data, ed->ed_self, key, &result);
	if (status != BSHELL_SUCCESS) {
		return FX_VALUE_EMPTY;
	}

	return result;
}

static enum bshell_status line_ed_put_data(
	struct bshell_line_ed_p *ed,
	const char *key,
	fx_value value)
{
	if (!ed->ed_data) {
		return BSHELL_ERR_NOT_SUPPORTED;
	}

	bshell_line_ed_plugin_class *ops = fx_object_get_interface(
		ed->ed_data,
		BSHELL_TYPE_LINE_EDITOR_PLUGIN);
	if (!ops || !ops->p_put_data) {
		return BSHELL_ERR_NOT_SUPPORTED;
	}

	return ops->p_put_data(ed->ed_data, ed->ed_self, key, &value);
}

fx_string *line_ed_get_prompt(struct bshell_line_ed_p *ed)
{
	if (ed->ed_cache.c_prompt) {
		return ed->ed_cache.c_prompt;
	}

	enum bshell_status status = BSHELL_SUCCESS;
	fx_value v = line_ed_get_data(ed, "prompt");
	if (!fx_value_is_set(&v)) {
		fx_string *prompt = fx_string_create();
		status = line_ed_put_data(
			ed,
			"prompt",
			FX_VALUE_OBJECT(prompt));
		if (status != BSHELL_SUCCESS) {
			fx_string_unref(prompt);
			return NULL;
		}

		ed->ed_cache.c_prompt = prompt;
		return prompt;
	}

	fx_value_get_object(&v, &ed->ed_cache.c_prompt);
	return ed->ed_cache.c_prompt;
}

fx_string *line_ed_get_buffer(struct bshell_line_ed_p *ed)
{
	if (ed->ed_cache.c_buffer) {
		return ed->ed_cache.c_buffer;
	}

	enum bshell_status status = BSHELL_SUCCESS;
	fx_value v = line_ed_get_data(ed, "buffer");
	if (!fx_value_is_set(&v)) {
		fx_string *buffer = fx_string_create();
		status = line_ed_put_data(
			ed,
			"buffer",
			FX_VALUE_OBJECT(buffer));
		if (status != BSHELL_SUCCESS) {
			fx_string_unref(buffer);
			return NULL;
		}

		ed->ed_cache.c_buffer = buffer;
		return buffer;
	}

	fx_value_get_object(&v, &ed->ed_cache.c_buffer);
	return ed->ed_cache.c_buffer;
}

static fx_tty *line_ed_get_tty(struct bshell_line_ed_p *ed)
{
	return ed->ed_tty;
}

static enum bshell_status line_ed_add_plugin(
	struct bshell_line_ed_p *ed,
	bshell_line_ed_plugin *plugin)
{
	bshell_line_ed_plugin_class *ops = fx_object_get_interface(
		plugin,
		BSHELL_TYPE_LINE_EDITOR_PLUGIN);
	if (!ops) {
		return BSHELL_ERR_INVALID_ARGUMENT;
	}

	if (ops->p_load) {
		ops->p_load(plugin, ed->ed_self);
	}

	fx_array_push_back(ed->ed_plugins, FX_VALUE_OBJECT(plugin));

	if (ops->p_render_buffer) {
		ed->ed_render_buffer = plugin;
	}

	if (ops->p_render_prompt) {
		ed->ed_render_prompt = plugin;
	}

	if (ops->p_get_data && ops->p_put_data) {
		ed->ed_data = plugin;
	}

	return BSHELL_SUCCESS;
}

static void line_ed_buffer_changed(struct bshell_line_ed_p *ed)
{
	const fx_iterator *it = fx_iterator_begin(ed->ed_plugins);
	fx_foreach(v, it)
	{
		bshell_line_ed_plugin *plugin = NULL;
		fx_value_get_object(v, &plugin);
		bshell_line_ed_plugin_class *ops = fx_object_get_interface(
			plugin,
			BSHELL_TYPE_LINE_EDITOR_PLUGIN);

		if (ops && ops->p_buffer_changed) {
			ops->p_buffer_changed(plugin, ed->ed_self);
		}
	}
	fx_iterator_unref(it);
}

static enum bshell_status readline(
	struct bshell_line_source *src,
	fx_stringstream *out)
{
	struct bshell_line_ed_p *ed
		= fx_unbox(struct bshell_line_ed_p, src, ed_linesrc);

	long r = line_ed_readline(ed, NULL);

	if (line_ed_is_eof(ed)) {
		return BSHELL_ERR_EOF;
	}

	fx_string *buf = line_ed_get_buffer(ed);
	if (buf) {
		fx_stream_write_cstr(out, fx_string_get_cstr(buf), NULL);
	}

	return BSHELL_SUCCESS;
}

/*** PUBLIC FUNCTIONS
 * *********************************************************/

enum bshell_status bshell_line_ed_readline(bshell_line_ed *ed, fx_string *out)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_readline,
		ed,
		out);
}

struct bshell_line_source *bshell_line_ed_get_line_source(bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_get_line_source,
		ed);
}

unsigned long bshell_line_ed_get_cursor(const bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_get_cursor,
		ed);
}

void bshell_line_ed_set_cursor(bshell_line_ed *ed, unsigned long cursor)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_set_cursor,
		ed,
		cursor);
}

unsigned long bshell_line_ed_move_cursor(bshell_line_ed *ed, long move_amount)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_move_cursor,
		ed,
		move_amount);
}

enum bshell_status bshell_line_ed_set_done(bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_set_done,
		ed);
}

enum bshell_status bshell_line_ed_set_eof(bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_set_eof,
		ed);
}

bool bshell_line_ed_is_done(const bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_is_done,
		ed);
}

bool bshell_line_ed_is_eof(const bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(BSHELL_TYPE_LINE_EDITOR, line_ed_is_eof, ed);
}

fx_string *bshell_line_ed_get_prompt(bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_get_prompt,
		ed);
}

fx_string *bshell_line_ed_get_buffer(bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_get_buffer,
		ed);
}

fx_tty *bshell_line_ed_get_tty(bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_get_tty,
		ed);
}

fx_value bshell_line_ed_get_data(const bshell_line_ed *ed, const char *key)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_get_data,
		ed,
		key);
}

void bshell_line_ed_put_data(
	bshell_line_ed *ed,
	const char *key,
	fx_value value)
{
	FX_CLASS_DISPATCH_STATIC_V(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_put_data,
		ed,
		key,
		value);
}

enum bshell_status bshell_line_ed_add_plugin(
	bshell_line_ed *ed,
	bshell_line_ed_plugin *plugin)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_add_plugin,
		ed,
		plugin);
}

void bshell_line_ed_buffer_changed(bshell_line_ed *ed)
{
	FX_CLASS_DISPATCH_STATIC_V0(
		BSHELL_TYPE_LINE_EDITOR,
		line_ed_buffer_changed,
		ed);
}

/*** VIRTUAL FUNCTIONS
 * ********************************************************/

static void init(fx_object *obj, void *priv)
{
	struct bshell_line_ed_p *ed = priv;

	ed->ed_self = obj;
	ed->ed_tty = fx_stdtty;
	ed->ed_plugins = fx_array_create();
	ed->ed_linesrc.s_readline = readline;
}

static void fini(fx_object *obj, void *priv)
{
	struct bshell_line_ed_p *ed = priv;

	clear_cache(ed);
	line_ed_cleanup_keymap(&ed->ed_keymap);
	fx_array_unref(ed->ed_plugins);
}

FX_TYPE_CLASS_BEGIN(bshell_line_ed)
	FX_TYPE_VTABLE_INTERFACE_BEGIN(fx_object, FX_TYPE_OBJECT)
		FX_INTERFACE_ENTRY(to_string) = NULL;
	FX_TYPE_VTABLE_INTERFACE_END(fx_object, FX_TYPE_OBJECT)
FX_TYPE_CLASS_END(bshell_line_ed)

FX_TYPE_DEFINITION_BEGIN(bshell_line_ed)
	FX_TYPE_ID(0xc59de843, 0xea6a, 0x46d9, 0xb7fd, 0xa3777a40c4fa);
	FX_TYPE_NAME("bshell.line_editor");
	FX_TYPE_CLASS(bshell_line_ed_class);
	FX_TYPE_INSTANCE_PRIVATE(struct bshell_line_ed_p);
	FX_TYPE_INSTANCE_INIT(init);
	FX_TYPE_INSTANCE_FINI(fini);
FX_TYPE_DEFINITION_END(bshell_line_ed)